Dental handpiece.



A.FERNALD.

DENTAL `HANDPIECE.

APPLICATION FILED IuLYza. 1915.

1,170,524. Peeented Fe1 .8,1916.

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DENTAL HANDPECE.

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Speciioation of Letters Eatent.

Patented Feb.. 8, 1916.

Application filed J'uly 23, 17915. Serial No. 41,441.

To all whom t may concern i Be it known that l, Aniinnnnr FERNALD, a citizen of the-United States, residing at Boston, in the county of Suffolk and State of Massachusetts, have inventedcertain neur and useful Improvements in Dental Handthe following is a specification.

i The present invention relates to certain new and useful improvements in dental hand pieces, andilias for its objectto provide a device of this character which embodies novel features of construction whereby it can be used in places hitherto inaccessible to af power driven instrument, and by means of which. back cavities can be drilled out quickly without the tedious and painful use `ofa hand operated device.`

Further `objects of the invention are to provide a dental hand piece which is conipact inits construction and can be used for preparing cavities in the buccal or Vcheek side of the twelve year molar and wisdom teeth` without lacerating the cheeks or causing pain or inconvenience to the patient, Awhich can-be adjusted so as to be used to the p greatest advantage for` all lkinds of `worlnwwhich admits of a short drill` being used, and whichcan 'be ueasilycontrolled and-manipulated by the operator. y p i WViththese and other objects in vievv,the invention consists in certain novel combi `nations and arrangementsaof thepartsas lwill more fully appear as vthe description proceeds, the novel features thereof being pointed out in the appended claims.

v For `a full understanding` of the invention, reference is to be had to the following accompanying drawing, in

lligure lis aside, elevation of adental drillconstructed in accordance with the invent-ion, the head-being shown inone .position by-` fully linesand in different adjusted positionsby dottedlines. Fig.` Qis a longi tudinal sectional view through the instrufinent. F is a transverse sectional view on the line 3-8 of Fig. 2. i Fig. l is a similar `viewfon the linee-L of Fig. 2. Fig. 5

`isV a rear end view of the vtubular chuck,

showing the saine as removed from the inlstrument. 1 Fig. 6 `is a detailview of the drillV locking slide. n p lgCorrespending and like parts arerererred `to-in the following description and indicated `screws r vbodiinent of the invention, the numeral 1 designates a tubular .handle which is kiiui'led or rougliened upon the exterior thereof, as indicated at la, so as to be rcad ily grasped by the hand, and which is adapt- Y edto receive a flexible shaft 2 freni` a dental motor. Fitted within one end of the tubular handle 1 and projecting therefrom is a stock 3, said stock terminating at the outer end thereof in a hollow ball t upon which a substantially semispherical socket is loosely7 mounted. A driveshaft `G` extends axially through the stock 3 and is journaled therein, the rear end of the drive shaft being adapted to be connected in the usual manner to the flexible shaft 2. A pair of diametrically opposed pivot connect the socket 5 to the ball 4 so that the former can be swung back and forth upon the latter, and the socket `is provided at the pivot points thereof with rearwardly :projecting ears 51 adapted to cooperate with a collar 8 threaded upon the stock to lock the socket in different angu- .lar positions upon the ball.

Projecting` forwardly from the socket 5 and integral theiewith isan exteriorly threaded neck Sa upoi'iwhich the rear end of the right angle head 9 is `fitted. A shaft arranged withinthe hollow ball 1 at substantially the central portion thereof. A

ysleeved@ is slipped upon the. shaft 10 and f journaled within thencck Sa, the outer end ofthe sleeve terminating in abevel gear 13 "which bears against the end of the neck 8, while the inner end of the sleeve is formed which a tlireaded'` plug 16 isremovably fitted, a chuck receiving seat 17 being provided `at the asc of the lateral4 opening. A, tubular chuck 18 which is arranged at right anglesto the axis of the head 9 and faces the lateral opening of the head is ro- `10 extends tlirough the neck Srl of the socket 5 and is connected to the end of the drive shaft (i by means of a universal joint 1l thereof, an apertured plug fitted within the lateral opening, a tubular chuck journaled within the head and arranged with the bore thereof in registry with the aperture of the plug, a drill insertible into the tubular chuck through the aperture of the plug and having an annular groove in the side thereof, a locking slide mounted upon the head for engagement with the annular groove to retain the drill in position, a shaft extending longitudinally through the head, a sleeve slipped upon the shaft and journaled within the neck of the socket, said sleeve having an interlocking connection with the shaft, bevel gearing between the sleeve and the tubular chuck, and a universal joint arranged within .the hollow ball and connecting the shaft to the drive shaft.

4. A dental hand piece including a stock terminating in a hollow ball, a drive shaft extending through the stock and journaled therein, a socket pivotally mounted upon the ball and formed with a longitudinally extending neck, ears projecting rearwardly from the socket, a collar threaded upon the stock for cooperation with the ears to lock the socket in different angular positions, a

tubular head fitted upon the neck of the socket and provided at the end thereof with a` lateral opening, an upright plug fitted within the lateral opening, a tubular chuck journaled within the head with the bore thereof in registry with the aperture of the plug, a drill insertible through the apertured plug into the chuck and having an annular groove-therein, a locking slide mounted upon the head for engagement with the annular groove of the drill to retain the drill in position, a shaft extending longitudinally through the head, a sleeve slipped upon the shaft and journaled within the neck of the socket, said sleeve having an interlocking connectionwith the shaft, bevel gearing between the sleeve and the tubular chuck, and a ball and socket joint arranged within the hollow ball and connecting the shaft to the hollow drive shaft. I

In testimony whereof I aHiX my signature in the presence of two witnesses.

ADELBERT FERNALD. l

Witnesses C. W. GRAY, O. F. FERNALD.

Copies of this patent may be obtained for ve cents each, by addressing the Commissioner of Patents,

` Y Washington, D. C. 

